My wife has found that writing has given her the voice she was denied most of her life. She started out with a journal, then used that as a template to write her memoir.
Now she has a blog that she uses to bring awareness of the challenges of life for people living with PTSD as well as other mental health issues. Although she has only been doing it for about a year she is gaining quite a following.
She and her T believe it has been a great benefit to her healing process. They both strongly advocate that anyone suffering a mental health issue to write about the difficulties they face, the fears they have, and especially their hopes and dreams for the future. My wife strongly believes that this is one of the things that has helped her come as far as she has.